Crater Lake National Park was founded on May 22nd, 1902. It's the nation's fifth oldest national park and the only national park in Oregon. Further, Crater Lake is the deepest lake in the United States, the second deepest in North America and the ninth deepest in the world.
The park is made up of a caldera that was formed when Mount Mazama, previously a group of overlapping shield and composite volcanoes, erupted some 7,700 years ago. It was the largest eruption within the Cascade Volcanic Arc in at least a million years, one which destroyed Mount Mazama's summit and wiped away approximately one mile of the complex volcanoes' elevation.
I visited Crater Lake three times within the span of a year and each trip was a unique experience.